Computer Integrated Manufacturing (CIM) has been widely used in semiconductor device fabrication to control material and information flow. Fabrication automation enables efficient and accurate control of material movement and related data is of vital importance to decrease cycle time, reduce waste, and improve yield.
Even in some of the most automated manufacturing environments that use Automated Material Handling Systems (AMHS), some manual handling of materials are inevitable and necessary. When manual handling of materials occurs, there is a risk of a mismatch between the physical location of the material and the data maintained in the computer systems. In other words, the computer data tracking the location and processing of the materials becomes inaccurate and introduces errors in subsequent processing steps. Such material mismatch errors result in delays in cycle time, increased rework and scrap, and decreased yield.